Effects of climate change and contaminants on oxygen availability for marine biota

In marine productive ecosystems, cyclical fluctuations of temperature, oxygen, pH and light significantly influence marine life by determining tolerance and adaptation and affecting ecosystem functions and processes.

Oxygen is a fundamental factor for ecosystem functioning that has varied dramatically through the aeons, leading to significant extinctions and modulation of marine communities.

Climate change and anthropogenic pressures, such as eutrophication, have contributed substantially to ocean deoxygenation and exacerbated hypoxia levels, impacting the behaviour, physiology, and ecology of marine life.

This is particularly true for productive marine ecosystems that are often characterized by seasonal and diel fluctuations of oxygen.

Marine ecosystems, such as coral reefs, mangroves, and seagrasses, experience different daily oxygen conditions ranging from hyperoxia to anoxia.

Changing oxygen regimes on coral reefs have been exacerbated by anthropogenic factors at different spatiotemporal scales.

This variation affects the productivity, respiration, and calcification of reefs, and influences the interaction between corals, mutualists, competitors, and pathogens. To date, research has predominantly focused on deoxygenation and hypoxia.

Conversely, the study of the impacts of oxygen fluctuations at an ecologically relevant scale on coral reefs has received far less attention.

Therefore, in this PhD project I will identify and model the predictability, periodicity and magnitude of oxygen fluctuations in global coral reefs through time series analyses.

The information obtained will then be used to assess the impacts of oxygen fluctuations on coral ontogeny and reef organisms by using Trapezia crabs and Alpheus shrimps as model organisms.